Clinical utility of positron emission tomography in the diagnosis and management of periampullary neoplasms

Background: This study examined the effect that 18-fluorodeoxyglucose positron emission tomography (¹⁸FDG-PET) imaging had on the clinical management of patients with suspected periampullary malignancy. Methods: Fifty-four patients with suspected pancreatic neoplasms underwent both whole-body ¹⁸FDG-PET and abdominal computed tomography (CT). Malignant or benign disease was confirmed pathologically in 47 patients. Results: Of the 41 patients with malignancy, ¹⁸FDG-PET failed to identify the primary tumor in 5 patients. ¹⁸FDG-PET demonstrated increased uptake suggesting primary malignancy in 37 patients. Malignant pathology was confirmed in 36 cases. ¹⁸FDG-PET identified malignant locoregional lymph node metastases in six of ten patients. All nodes identified before surgery by ¹⁸FDG-PET were also seen on preoperative CT. Six patients who were thought to have resectable disease by CT were found to have distant metastasis at laparotomy. ¹⁸FDG-PET did not detect metastasis in any of these cases. Before surgery, ¹⁸FDG-PET identified distant metastases that were not detected by CT in one patient. Conclusions: Despite high sensitivity and specificity in diagnosing periampullary malignancy, ¹⁸FDG-PET did not change clinical management in the vast majority of patients previously evaluated by CT. In addition, ¹⁸FDG-PET missed > 10% of periampullary malignancies and did not provide the anatomical detail necessary to define unresectabilty.